To compare the clinical outcome 2 years after corneal collagen cross-linking (CXL) with conventional and accelerated ultraviolet A (UVA) irradiation using riboflavin with hydroxypropyl methylcellulose.
Prospective randomized controlled study. Forty patients with keratoconus (40 eyes) were randomized to either CXL using conventional 3 mW/cm2 UVA irradiation for 30 minutes (CXL30 group) or accelerated 9 mW/cm2 UVA irradiation for 10 minutes (CXL10 group). In both groups, a solution of 0.1% riboflavin with 1.1% hydroxypropyl methylcellulose (methylcellulose–riboflavin) was used. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), and Scheimpflug tomography were performed at baseline and after 24 months.
Both groups had statistically significant improvement in CDVA and maximum keratometric reading compared with baseline; however, with no statistically significant difference in the change between the 2 groups. No significant changes in flattest, steepest and mean keratometry (K1, K2 and K mean) were found in either of the groups. There were no statistically significant changes in ECD in either group after 2 years or in the difference in the change between the 2 groups. A literature review showed comparative clinical outcome after accelerated CXL compared with conventional CXL; however, in several studies, there was a tendency for less pronounced corneal flattening after accelerated CXL.
Improvement in visual acuity and maximum keratometric reading 2 years after CXL was found after both conventional and accelerated UVA irradiation using methylcellulose–riboflavin. This suggests that when using riboflavin with methylcellulose, the less time-consuming accelerated protocol is a valuable and effective option in CXL treatment.
*Department of Ophthalmology, Oslo University Hospital, Norway; and
†Centre for Eye Research, University of Oslo, Norway.
Correspondence: Anne Marie Hagem, MD, Department of Ophthalmology, Oslo University Hospital HF Ullevål, Postboks 4950 Nydalen, 0424 Oslo, Norway (e-mail: firstname.lastname@example.org).
The authors have no funding or conflicts of interest to disclose.
Received June 20, 2018
Accepted September 07, 2018